1. Field of the Invention
This connection relates to multi-contact electrical connectors. Particularly, the invention relates to X-ray radiation resistant connectors. More particularly, the invention relates to a receptacle section of a connector which receptacle is resistant to radio frequency interference and to X-ray radiation interference.
2. Description of the Prior Art
Multi-contact electrical connectors are expected to shield out at least a substantial proportion of the electromagnetic energy given off by natural sources or by man-made electronic devices or explosions, such as radar over naval vessels and military air bases, the electromagnetic pulses (EMP) resulting from a nuclear explosion. It is desirable to shield against both radio frequency radiation (RFI) and against X-ray radiation. RFI radiation entering by way of a connector can upset or even black out for a time the internal electrical circuitry to which the connector is wired. X-ray radiation which penetrates the connector can generate spurious electrical impulses in the conductors and damage the non-metallic materials, such as plastic insulators and organic coatings on wire leads from internal circuitry to the connector.
In general, various connectors are known which more or less acceptably perform one, but not both, of these shielding functions.
When a connector is disengaged (unmated) the receptacle is normally open to the atmosphere and radiation which strikes on the open face of the receptacle readily enters the internal circuitry by way of the exposed sockets. Various expedients for eliminating this entry have been tried. Metal trap doors are the most commonly used. These trap doors are complex and have low reliability. Severe radiation environments tend to decrease the protection provided by such doors. An especially efficient shield for RFI in open faced receptacles is provided by the "EMIGrid" system disclosed in J. J. Phillips U.S.A. Pat. No. 3,550,065, granted Dec. 22, 1970.
Most electrical connectors are provided with locking-unlocking devices. A collet finger device working on the outer periphery of the receptacle housing is disclosed in T. A. Clark U.S.A. Pat. No. 3,594,694, granted July 20, 1971.
Some electrical connectors are provided with center lock-unlock mechanisms. Flat pack connectors can conveniently use center locks. The present connectors using center locks are extremely leaky to EMI in the flat pack configuration.